diff options
Diffstat (limited to 'arch/powerpc/mm/hash64_64k.c')
| -rw-r--r-- | arch/powerpc/mm/hash64_64k.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c new file mode 100644 index 000000000000..0762c1e08c88 --- /dev/null +++ b/arch/powerpc/mm/hash64_64k.c @@ -0,0 +1,322 @@ +/* + * Copyright IBM Corporation, 2015 + * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + */ + +#include <linux/mm.h> +#include <asm/machdep.h> +#include <asm/mmu.h> +/* + * index from 0 - 15 + */ +bool __rpte_sub_valid(real_pte_t rpte, unsigned long index) +{ + unsigned long g_idx; + unsigned long ptev = pte_val(rpte.pte); + + g_idx = (ptev & _PAGE_COMBO_VALID) >> _PAGE_F_GIX_SHIFT; + index = index >> 2; + if (g_idx & (0x1 << index)) + return true; + else + return false; +} +/* + * index from 0 - 15 + */ +static unsigned long mark_subptegroup_valid(unsigned long ptev, unsigned long index) +{ + unsigned long g_idx; + + if (!(ptev & _PAGE_COMBO)) + return ptev; + index = index >> 2; + g_idx = 0x1 << index; + + return ptev | (g_idx << _PAGE_F_GIX_SHIFT); +} + +int __hash_page_4K(unsigned long ea, unsigned long access, unsigned long vsid, + pte_t *ptep, unsigned long trap, unsigned long flags, + int ssize, int subpg_prot) +{ + real_pte_t rpte; + unsigned long *hidxp; + unsigned long hpte_group; + unsigned int subpg_index; + unsigned long rflags, pa, hidx; + unsigned long old_pte, new_pte, subpg_pte; + unsigned long vpn, hash, slot; + unsigned long shift = mmu_psize_defs[MMU_PAGE_4K].shift; + + /* + * atomically mark the linux large page PTE busy and dirty + */ + do { + pte_t pte = READ_ONCE(*ptep); + + old_pte = pte_val(pte); + /* If PTE busy, retry the access */ + if (unlikely(old_pte & _PAGE_BUSY)) + return 0; + /* If PTE permissions don't match, take page fault */ + if (unlikely(access & ~old_pte)) + return 1; + /* + * Try to lock the PTE, add ACCESSED and DIRTY if it was + * a write access. Since this is 4K insert of 64K page size + * also add _PAGE_COMBO + */ + new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED | _PAGE_COMBO; + if (access & _PAGE_RW) + new_pte |= _PAGE_DIRTY; + } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, + old_pte, new_pte)); + /* + * Handle the subpage protection bits + */ + subpg_pte = new_pte & ~subpg_prot; + rflags = htab_convert_pte_flags(subpg_pte); + + if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) { + + /* + * No CPU has hugepages but lacks no execute, so we + * don't need to worry about that case + */ + rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); + } + + subpg_index = (ea & (PAGE_SIZE - 1)) >> shift; + vpn = hpt_vpn(ea, vsid, ssize); + rpte = __real_pte(__pte(old_pte), ptep); + /* + *None of the sub 4k page is hashed + */ + if (!(old_pte & _PAGE_HASHPTE)) + goto htab_insert_hpte; + /* + * Check if the pte was already inserted into the hash table + * as a 64k HW page, and invalidate the 64k HPTE if so. + */ + if (!(old_pte & _PAGE_COMBO)) { + flush_hash_page(vpn, rpte, MMU_PAGE_64K, ssize, flags); + old_pte &= ~_PAGE_HASHPTE | _PAGE_F_GIX | _PAGE_F_SECOND; + goto htab_insert_hpte; + } + /* + * Check for sub page valid and update + */ + if (__rpte_sub_valid(rpte, subpg_index)) { + int ret; + + hash = hpt_hash(vpn, shift, ssize); + hidx = __rpte_to_hidx(rpte, subpg_index); + if (hidx & _PTEIDX_SECONDARY) + hash = ~hash; + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += hidx & _PTEIDX_GROUP_IX; + + ret = ppc_md.hpte_updatepp(slot, rflags, vpn, + MMU_PAGE_4K, MMU_PAGE_4K, + ssize, flags); + /* + *if we failed because typically the HPTE wasn't really here + * we try an insertion. + */ + if (ret == -1) + goto htab_insert_hpte; + + *ptep = __pte(new_pte & ~_PAGE_BUSY); + return 0; + } + +htab_insert_hpte: + /* + * handle _PAGE_4K_PFN case + */ + if (old_pte & _PAGE_4K_PFN) { + /* + * All the sub 4k page have the same + * physical address. + */ + pa = pte_pfn(__pte(old_pte)) << HW_PAGE_SHIFT; + } else { + pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; + pa += (subpg_index << shift); + } + hash = hpt_hash(vpn, shift, ssize); +repeat: + hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; + + /* Insert into the hash table, primary slot */ + slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0, + MMU_PAGE_4K, MMU_PAGE_4K, ssize); + /* + * Primary is full, try the secondary + */ + if (unlikely(slot == -1)) { + hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; + slot = ppc_md.hpte_insert(hpte_group, vpn, pa, + rflags, HPTE_V_SECONDARY, + MMU_PAGE_4K, MMU_PAGE_4K, ssize); + if (slot == -1) { + if (mftb() & 0x1) + hpte_group = ((hash & htab_hash_mask) * + HPTES_PER_GROUP) & ~0x7UL; + ppc_md.hpte_remove(hpte_group); + /* + * FIXME!! Should be try the group from which we removed ? + */ + goto repeat; + } + } + /* + * Hypervisor failure. Restore old pmd and return -1 + * similar to __hash_page_* + */ + if (unlikely(slot == -2)) { + *ptep = __pte(old_pte); + hash_failure_debug(ea, access, vsid, trap, ssize, + MMU_PAGE_4K, MMU_PAGE_4K, old_pte); + return -1; + } + /* + * Insert slot number & secondary bit in PTE second half, + * clear _PAGE_BUSY and set appropriate HPTE slot bit + * Since we have _PAGE_BUSY set on ptep, we can be sure + * nobody is undating hidx. + */ + hidxp = (unsigned long *)(ptep + PTRS_PER_PTE); + rpte.hidx &= ~(0xfUL << (subpg_index << 2)); + *hidxp = rpte.hidx | (slot << (subpg_index << 2)); + new_pte = mark_subptegroup_valid(new_pte, subpg_index); + new_pte |= _PAGE_HASHPTE; + /* + * check __real_pte for details on matching smp_rmb() + */ + smp_wmb(); + *ptep = __pte(new_pte & ~_PAGE_BUSY); + return 0; +} + +int __hash_page_64K(unsigned long ea, unsigned long access, + unsigned long vsid, pte_t *ptep, unsigned long trap, + unsigned long flags, int ssize) +{ + + unsigned long hpte_group; + unsigned long rflags, pa; + unsigned long old_pte, new_pte; + unsigned long vpn, hash, slot; + unsigned long shift = mmu_psize_defs[MMU_PAGE_64K].shift; + + /* + * atomically mark the linux large page PTE busy and dirty + */ + do { + pte_t pte = READ_ONCE(*ptep); + + old_pte = pte_val(pte); + /* If PTE busy, retry the access */ + if (unlikely(old_pte & _PAGE_BUSY)) + return 0; + /* If PTE permissions don't match, take page fault */ + if (unlikely(access & ~old_pte)) + return 1; + /* + * Check if PTE has the cache-inhibit bit set + * If so, bail out and refault as a 4k page + */ + if (!mmu_has_feature(MMU_FTR_CI_LARGE_PAGE) && + unlikely(old_pte & _PAGE_NO_CACHE)) + return 0; + /* + * Try to lock the PTE, add ACCESSED and DIRTY if it was + * a write access. Since this is 4K insert of 64K page size + * also add _PAGE_COMBO + */ + new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED; + if (access & _PAGE_RW) + new_pte |= _PAGE_DIRTY; + } while (old_pte != __cmpxchg_u64((unsigned long *)ptep, + old_pte, new_pte)); + + rflags = htab_convert_pte_flags(new_pte); + + if (!cpu_has_feature(CPU_FTR_NOEXECUTE) && + !cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) + rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap); + + vpn = hpt_vpn(ea, vsid, ssize); + if (unlikely(old_pte & _PAGE_HASHPTE)) { + /* + * There MIGHT be an HPTE for this pte + */ + hash = hpt_hash(vpn, shift, ssize); + if (old_pte & _PAGE_F_SECOND) + hash = ~hash; + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += (old_pte & _PAGE_F_GIX) >> _PAGE_F_GIX_SHIFT; + + if (ppc_md.hpte_updatepp(slot, rflags, vpn, MMU_PAGE_64K, + MMU_PAGE_64K, ssize, flags) == -1) + old_pte &= ~_PAGE_HPTEFLAGS; + } + + if (likely(!(old_pte & _PAGE_HASHPTE))) { + + pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT; + hash = hpt_hash(vpn, shift, ssize); + +repeat: + hpte_group = ((hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; + + /* Insert into the hash table, primary slot */ + slot = ppc_md.hpte_insert(hpte_group, vpn, pa, rflags, 0, + MMU_PAGE_64K, MMU_PAGE_64K, ssize); + /* + * Primary is full, try the secondary + */ + if (unlikely(slot == -1)) { + hpte_group = ((~hash & htab_hash_mask) * HPTES_PER_GROUP) & ~0x7UL; + slot = ppc_md.hpte_insert(hpte_group, vpn, pa, + rflags, HPTE_V_SECONDARY, + MMU_PAGE_64K, MMU_PAGE_64K, ssize); + if (slot == -1) { + if (mftb() & 0x1) + hpte_group = ((hash & htab_hash_mask) * + HPTES_PER_GROUP) & ~0x7UL; + ppc_md.hpte_remove(hpte_group); + /* + * FIXME!! Should be try the group from which we removed ? + */ + goto repeat; + } + } + /* + * Hypervisor failure. Restore old pmd and return -1 + * similar to __hash_page_* + */ + if (unlikely(slot == -2)) { + *ptep = __pte(old_pte); + hash_failure_debug(ea, access, vsid, trap, ssize, + MMU_PAGE_64K, MMU_PAGE_64K, old_pte); + return -1; + } + new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE; + new_pte |= (slot << _PAGE_F_GIX_SHIFT) & (_PAGE_F_SECOND | _PAGE_F_GIX); + } + *ptep = __pte(new_pte & ~_PAGE_BUSY); + return 0; +} |